In a class action suit filed by residents of Fukushima Prefecture who evacuated to Gunma Prefecture and elsewhere due to the ongoing Fukushima No. 1 nuclear plant disaster, the Maebashi District Court ordered both the plant operator, Tokyo Electric Power Co. (TEPCO), and the central government to pay 62 residents a total of 38.55 million yen. It marked the first time that the judiciary recognized the state's responsibility for negligence in the nuclear disaster.

The court ruling should be seen as admonition from the judiciary that the state has a grave responsibility over its nuclear power policy.

The main focus of the case was on whether TEPCO had been able to predict the size of the tsunami that struck the plant on March 11, 2011, and whether the state should have exercised its regulatory authority to make TEPCO implement necessary safety measures.

The plaintiffs focused on a long-term assessment on earthquakes, which the government released in 2002, as evidence to show that TEPCO had been able to predict a tsunami like the one that hit the Fukushima plant. The report stated that there was about a 20 percent chance that an earthquake of around magnitude 8 would occur off the coast between the northern Sanriku region and the Boso Peninsula within the next 30 years.

Based on this report, TEPCO predicted in 2008 that tsunami with a maximum height of 15.7 meters could hit the Fukushima No. 1 plant. The actual tsunami that hit the nuclear power station on March 11, 2011, however, was 15.5 meters tall. The plaintiffs argued that if TEPCO had taken the appropriate anti-tsunami measures based on the long-term assessment and other specific forecasts, the nuclear crisis could have been avoided.

The Maebashi District Court ruled almost entirely in favor of the plaintiffs, saying that TEPCO neglected to take measures despite having been able to predict that such a large tsunami could hit the nuclear plant, putting cost-cutting ahead of safety.

The court also handed down a similar decision regarding the culpability of the central government. Nuclear disasters cause irreparable damage over a large area. The court ruled that the fact that the central government did not exercise its regulatory authority even though TEPCO's anti-tsunami measures were insufficient was extremely unreasonable when considering the import of the Nuclear Reactor Regulation Law and other rules. It is notable, also, that the court ruled that the state's responsibility was on par with that of TEPCO's, and ordered the state to pay the plaintiffs the same amount in damages as the utility.

At the same time, however, the ruling was parsimonious in the compensation amount that it ordered be paid to the individual plaintiffs. Because the court deducted compensation money that TEPCO has already paid, the amount it approved was far below what the plaintiffs had demanded.

The plaintiffs had demanded 11 million yen per person -- including for those who had evacuated voluntarily -- citing loss of their hometowns and jobs, and grave emotional distress. For many of the plaintiffs, therefore, the ruling has likely come as a disappointment.

Around 30 similar lawsuits have been filed nationwide, by around 12,000 plaintiffs who have evacuated from Fukushima Prefecture. Rulings have not yet been handed down in any of those cases.

Why wasn't the disaster prevented? Who is responsible? Much of the public is still seeking answers to these questions.

However, the nuclear disaster investigative committees of both the government and the Diet have disbanded, bringing their respective probes into causes of the crisis to a halt. The lessons from the ongoing disaster have yet to be learned in their entirety. It is because a single nuclear incident has grave and far-reaching consequences that an examination of its cause is so important.